BN  BN::operator+(BN & second_number)
{
    unsigned long int R;
    unsigned short k=0;
    int i;
    if(*this>=second_number)
    {
        if (second_number.len==1&&second_number.number[0]==0)
            return *this;

        BN result(len+1,0);
        result.len=len+1;
        for(i=0;i<second_number.len;++i)
        {

            R=number[i]+second_number.number[i]+k;
            result.number[i]=BASE(R);
            //cout<<hex<<result.number[i]<<" ";
            k=R>>sizeof(BASE)*8;
        }



        {
            while(i<len)
            {
                R=number[i]+k;

                result.number[i]=BASE(R);
                //cout<<hex<<result.number[i]<<" ";
                k=R>>sizeof(BASE)*8;
                ++i;
            }

            while(i<result.len)
            {
                R=result.number[i]+k;

                result.number[i]=BASE(R);
                //cout<<hex<<result.number[i]<<" ";
                k=R>>sizeof(BASE)*8;
                ++i;
            }
        }
        //result.sub_null();
        //cout<<result<<endl;
        //cout<<endl;
        return result;
    }

    else
    {
        if (len==1&&number[0]==0)
            return second_number;
        BN result(second_number.len+1,0);
        result.len=second_number.len+1;
        for(i=0;i<len;++i)
        {
            R=number[i]+second_number.number[i]+k;
            result.number[i]=BASE(R);
            //cout<<hex<<result.number[i]<<" ";
            k=R>>sizeof(BASE)*8;
        }



            while(i<second_number.len)
            {
                R=second_number.number[i]+k;
                result.number[i]=BASE(R);
                //cout<<hex<<result.number[i]<<" ";
                k=R>>sizeof(BASE)*8;
                ++i;
            }

            while(i<result.len)
            {
                R=result.number[i]+k;

                result.number[i]=BASE(R);
                //cout<<hex<<result.number[i]<<" ";
                k=R>>sizeof(BASE)*8;
                ++i;
            }
        //cout<<endl;
        //result.sub_null();
        return result;

    }
}